My data follows a sigmoidal function of the form
I have taken the function from the SSLogis function in R.
My supervisor and I think that there is a second variable that influences the asymptote and scale of the function.
So I'm stuck with the questions:
1. Is it at all possible to do a multiple regression based on this function?
If yes, 2. Is it possible to transform the sigmoidal to a linear function and use it in a multiple linear regression?
Or 3. Is there a way to do a multiple non-linear regression?
Any help is really welcome.